Car wash systems generally include drying stations which utilize flexible inflatable bags for removing fluid from a vehicle surface to dry the vehicle. Rollers have been connected to the end portions of the nozzles of the bag to engage the surface of the passing vehicle. Such is disclosed in U.S. Pat. No. 4,446,592, issued May 8, 1984 in the name of McElroy and assigned to the assignee of the subject invention.
It has become desirable to eliminate nozzle/air bag contacting the vehicle by providing a proximity sensor to sense the location of the vehicle with respect to the nozzle, and maintaining a predetermined distance therebetween. Automotive car drying systems have been proposed which utilize ultrasonics to sense the distance of the vehicle from the drying system. One such system is illustrated in U.S. Pat. No. 4,995,136, issued Feb. 26, 1991 in the name of Smith. The blower bag of the system is positioned according to an output signal from an ultrasonic imaging sensor mounted on support frame of the system. The relative position of the blower bag is measured by a linear potentiometer mounted to the piston which positions the blower. The sensor output is compared with the potentiometer output to adjust the arm to control the height of the bag from the vehicle.
U.S. Pat. No. 4,949,423, issued Aug. 21, 1990 in the name of Larson et al discloses a dryer for automatic car wash equipment utilizing two sensors to maintain the nozzle within a preselected proximity range of the top portions of the vehicle; one sensor for detecting the proximity of a nozzle to opaque top portions of the vehicle, and one sensor for detecting the proximity of the nozzle to transparent top portions of the vehicle. The means by which the nozzle is mounted and moved toward and away from the vehicles vary the orientation of the nozzle relative to vertical as the nozzles move between their uppermost and lowermost positions.
U.S. Pat. No. 4,587,688, issued May 13, 1986 in the name of Gougoulas discloses a proximity detector for car dryer equipment. The height of the dryer is adjusted by a sonar proximity detector. The sonar detector transmits a signal and receives the reflection to detect the distance by elapsed time between the transmitted and received signals.